DVM Reproductive Medicine and Theriogenology 2

Question 1

Superovulation in cattle for embryo transfer is most commonly induced by:

Accepted Answer

Exogenous FSH or eCG administered during the mid-luteal phase to stimulate multiple follicle development

Answer

Multiple ovulations for embryo transfer are induced by exogenous FSH (given in decreasing doses over 4 days) or a single eCG injection during the mid-luteal phase, resulting in several transferable embryos.

Question 2

In swine, maternal recognition of pregnancy requires a minimum number of viable embryos because:

Accepted Answer

Fewer than 4–5 embryos produce insufficient estrogen to rescue corpora lutea from prostaglandin-mediated regression

Answer

Porcine embryos must produce sufficient estrogen by days 11–12 to redirect uterine PGF2α secretion away from the vasculature, rescuing the CL; fewer than approximately 4–5 embryos fails to provide adequate signal.

Question 3

Rectal palpation of pregnancy in mares typically becomes reliably diagnostic at approximately:

Accepted Answer

Day 25–30

Answer

Although ultrasound detects equine pregnancy from day 10–12, rectal palpation reliably identifies pregnancy at approximately day 25–30 when the uterine bulge and altered uterine tone are palpable.

Question 4

Prolonged diestrus (persistent corpus luteum) in mares is characterized by:

Accepted Answer

Failure of the CL to regress beyond the normal luteal phase, with sustained progesterone suppressing estrus

Answer

Persistent CL in mares occurs when normal PGF2α-mediated luteolysis fails, often following early embryonic death, resulting in persistently elevated progesterone and behavioral anestrus.

Question 5

The standard cryoprotectant used in equine semen cryopreservation is:

Accepted Answer

Glycerol

Answer

Glycerol (typically 2–5%) is the standard cryoprotectant for stallion semen freezing; it penetrates sperm membranes and protects against intracellular ice crystal formation during cryopreservation.

DVM - Doctor of Veterinary Medicine Practice Test

DVM - Doctor of Veterinary Medicine Practice Test

DVM Reproductive Medicine and Theriogenology 2